The present invention relates to automatic transmissions and, more particularly, to a hydraulic valve repair kit and method of use, which functions to extend the useful service life of a hydraulic spool valve within the valve body of a transmission.
Automatic transmission systems of the prior art have a hydraulic circuit sub-system which includes at least a hydraulic pump, a valve body having fluid conducting passages or circuits, input and exhaust ports formed within the fluid circuits, and a plurality of spool valves so-called because of their resemblance to sewing thread type spools. Such valves are comprised of cylindrical pistons having control diameters or lands formed thereon, which alternately open and close the ports to the fluid circuits to regulate the flow and pressure of automatic transmission fluid (hereinafter xe2x80x9cATFxe2x80x9d) within the fluid circuits to actuate different components of the transmission. It will be understood that in describing hydraulic circuits, ATF usually changes names when it passes through an orifice or control valve in a specific fluid circuit.
Typically such a spool valve undergoes continuous reciprocating movement due to fluctuation in hydraulic line pressure, which can result in premature wear and improper shifting problems in the transmission. More particularly, the end faces of such a spool valve can be damaged by continuous striking against the interior of the valve body and other internal components such a spring retainer plate during operation resulting in jamming and failure of the hydraulic circuit requiring complete transmission overhaul.
Thus, the present invention has been developed to resolve this problem and other shortcomings of the prior art.
Accordingly, the present invention is a spool valve repair kit comprising a valve cap and a replacement spring retainer plate, which are utilized in combination to repair the original equipment manufacture (hereinafter xe2x80x9cOEMxe2x80x9d) spool valve to increase the service longevity of such a spool valve in the valve body of an automatic transmission. The valve cap is a cylindrical construction, which is radially disposed about a terminal end of the valve piston to provide a durable contact surface for the valve piston. The spring retainer plate is also redesigned to prevent damage to the aformentioned contact surface and to provide a stable spring seat for a compression spring, which improves the accuracy of the valve""s operation.